Brake mechanism.



W. P. COLLINS. BRAKE MECHANISM. APPLICATION FILED FEB. 25, 1913.

Patented Apr. 14, 1914.

K011221556 es. 9

WILLIAM P. COLLINS, F BOSTON, MASSACHUSETTS, ASSIGNOR 'IO AUTOMATIC AIR BRAKE COMPANY, CI-IUSETTS.

OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSA- BRAKE MECHANISM.

Specification of Letters Patent.

Patented Apr. 1d, 1914.

Application filed February 25, 1913. Serial No. 750,518.

1/ '0 all 107mm it may concern:

Be it known that I, WILLIAM P. COLLINS, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented new and useful Improvements in Brake Mechanisms,

' of which the following is a specification.

This invention relates to new and useful improvements in brake mechanisms.

The object of the invention is to provide a powerful, compact and durable brake mecha nism having a rotatable member which is adapted to be retarded or checked by controlling the passage of the fluid driven by said rotating member, whereby friction and wear between the moving parts of said brake mechanism will be reduced to a minimum.

The object of the invention is further to provide a valve adapted to gradually check the passage of said fluid.

The invention consists in the combination and arrangement of parts whereby the above objects and certain other objects hereinafter appearing are attained, as set forth in the following specification and particularly pointed out in the claims.

Referring to the drawings: Figure 1 is a transverse section, partly in elevation, of a brake embodying my invention. Fig. 2 is a sectional elevation of the device taken on line 2-2 of Fig. 1. Fig. 3 is a detail section, partly in elevation, taken on line 33 of Fig. 1 illustrating one means for opening and closing the ports.

Like numerals refer to like parts through out the several views of the drawings.

In the drawings, 5 is a casing which is preferably constructed. in three parts comprising the cylindrical side wall 6 and the end walls 7 and 8, said three parts being preferably secured together by bolts 9. A piston blade carrier 10 is arranged within the casing 5 and is secured to a. shaft 11 having bearings 12 and 13 in the end walls 7 and 8 respectively. The carrier 10 is preferably provided with a cylindrical outer periphery 14.

A portion of the inner wall of the casing 5 is arranged concentric with the median axial line of the shaft 11, while the inner wall of the remaining portionof said casing is substantially eccentrically arranged relatively to said median axial line and forms a chamber 15 having, adjacent opposite ends thereof, ports 16 and 17.

The carrier 10 is provided with a series of radially disposed slots 18 within which pis tons 19 are placed, said pistons preferably comprising a plurality of relatively movable blades 20 which during the relative movements between said casing and said rotary member are adapted to move radially within said slots 18 and to engage the inner wall of the casing 5.

In operating the device either the casing 5 or the carrier 10 may be rotated relatively to the other, or both of said members may be rotated in opposite directions.

The preferred method of operating the device however is to rotate the carrier 10 for the reason that in so doing the centrifugal force tends to retain said pistons, or the several blades comprising said pistons, in engagement at their outer ends with the inner wall of said casing 5 or particularly that portion of the wall of the casing which lies concentric with the median axial line of said shaft 11.

As the carrier 10 is rotated in the direction of the arrow a Fig. 1 and the pistons 19 approach the chamber 15, for fear the centrifugal force will not always be sufficient to provide a proper contact between said pistons 19 and the wall of the casing 5 constituting said chamber, I have provided means adapted to move said pistons radially relatively to the carrier 10 and to retain said pistons in contact with said wall, said means preferably including a cylindrical member 21 arranged to revolve about an axis substantially concentric with the eccentrically arranged wall of the casing 5 constituting the outer wall of the chamber 15.

The member 21 is constructed in the form of a ring. and is arranged within the carrier 10 to revolve upon rollers 22 journaled upon studs 23.

In the present invention the carrier 10 is provided with recesses 21, 21, at opposite ends thereof respectively and therefore to evenly and uniformly sustain the pistons 19 in their proper relation to the wall constituting said chamber 15 two cylindrical members are provided, one within each of said recesses, said studs 23, which support the rollers 22 constituting bearings for said rings, being mounted in the end walls 7 and 8 of said casing 5. The rings 21 preferably engage the inner periphery of the carrier 10 and as said carrier is rotated, said ring will be revolved upon the rollers 22, there being two of said rollers to retain said ring concentric with said eccentrically arranged wall.

As the -arrier is rotated, as hereinbefore described in the direction of the arrow a, the pistons 19 as they approach and enter the chamber 15 will drive in advance thereof the air, liquid or whatever fluid it is found most desirable to employ therein, causing said fluid to be ejected through the port 17, providing said port is open, .while a partial vacuum will be formed at the rear of said piston causing air to enter said chamber through the port 16 providing said latter port is open and consequently retarding the movement of said rotatable member but little or none.

When it is desired to check or slightly retard the movements of said carrier relatively to the casing 5, the ports 16 and 17 are slightly closed or completely closed as the case may be by means hereinafter described. lVhen said ports are partially closed, the pistons 19 as they enter the chamber 15 and pass the port 16 will, owing to the increasing cross sectional area of said chamber,

gradually suck the air into said chamber through said port until they arrive at the point b, which is the deepest portion of said casing, the air then bet-ween the piston at said point and the next succeeding piston will be carried around with said rotary member until said piston and said succeeding piston arrive at positions upon opposite sides of and equidistant from the point b then upon the continued movement of said pistons the air therebetween will be gradually compressed owing to the gradually decreasing cross sectional area of said chamber 15 and consequently the movement of said carrier will be retarded.

When it is desired to completely stop said carrier the ports 16 and 17 are completely closed preventing both the intake and the discharge of the air to and from said chamber 15. In completely closing said ports however it is necessary that said closing be gradual in order to prevent an excessive shock to the moving parts of the device. To accomplish this, valves are provided for said ports each of which include a rotary screwthreaded member 24, the screw-threads thereof being of exceedingly sharp pitch and engage corresponding threads formed preferably upon the exterior of a stem 25. This stem is further provided with a series of passages 26 which extend radially through said stem opening into a passage 27 which comconstituting a needle valve, which extends inwardly into the passage 27 The member 24 is further provided with openings 29 arranged about the projection 28 and as said member is moved longitudinally of the stem 25 said projection will open and close the end of the passage 28 and thus prevent the escapement or admission of more or less air or liquid through said passage.

A rotary motion is imparted to the member 24: by a lever 30 which in turn is preferably actuated by a lever'31 connected to said lever 30 by a link 32, said link extending from the operating lever 30 of one of said valves to the operating lever 30 of the other of said valves thus causing said valves to be simultaneously opened or closed.

Having thus described my invention what I claim and desire by Letters Patent to secure is: g

A device of the class described having, in combination, a cylindrical piston blade carrier, a casing within which said carrier is arranged, said casing having a' chamber formed outside of and adjacent to the periphery of said carrier, the inner wall of said casing within said chamber being eccentrically arranged relatively to the aXis of said carrier, said chamber having ports adjacent opposite ends thereof, piston blades on said carrier adapted to engage the inner wall of said casing, means to create a relative rotary movement between said carrier and said casing, means to cause said blades to engage the inner wallconstituting said chamber during said rotary movement, said means including rings mounted to revolve about an axis substantially coincident with the axis of said eccentrically arranged wall, said rings adapted to be engaged by said pistons only when said pistons are passing through said chamber, rollers adapted to support said rings, and means to open and close said ports.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

-WILLIAM P. COLLINS. WVitnesses SYDNEY E. TAFT, LEONARD A. POWELL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

